Midwifery care and medical complications: the role of risk screening.

This study analyzed the 147,293 births attended by midwives in the United States in 1989. It used the revised and expanded standard national certificate of a live birth, which for the first time systematically records prenatal medical risk, intrapartum complications, obstetric procedures, and birth outcomes. It builds on earlier findings of positive outcomes for midwife-attended births to examine the prenatal medical risk profile of mothers served by midwives, the performance of obstetric procedures by midwives in different birth settings, more specific measures of outcomes, and possible explanations for these findings. Although midwives attending births in birth centers and homes generally serve mothers who are at much less than average medical risk, and in cases of intrapartum complications risk screening appears to occur, nurse-midwife-attended births in hospitals involve mothers whose risk profiles compare with, and in some cases are worse than, the national average. Nonetheless, the outcomes of these births are better than the national average. Mothers attended by midwives in birth centers and homes also have a different pattern of prenatal care, which begins later and includes fewer visits, but gives more apparent attention to self-care, and results in less smoking and alcohol use and greater weight gain.